The molecular structure of mammalian primary cilia revealed by cryo-electron tomography

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Petra Kiesel - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)
  • Gonzalo Alvarez Viar - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)
  • Nikolai Tsoy - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)
  • Riccardo Maraspini - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)
  • Peter Gorilak - , Institute of Molecular Genetics of the Czech Academy of Sciences (Author)
  • Vladimir Varga - , Institute of Molecular Genetics of the Czech Academy of Sciences (Author)
  • Alf Honigmann - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)
  • Gaia Pigino - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)

Abstract

Primary cilia are microtubule-based organelles that are important for signaling and sensing in eukaryotic cells. Unlike the thoroughly studied motile cilia, the three-dimensional architecture and molecular composition of primary cilia are largely unexplored. Yet, studying these aspects is necessary to understand how primary cilia function in health and disease. We developed an enabling method for investigating the structure of primary cilia isolated from MDCK-II cells at molecular resolution by cryo-electron tomography. We show that the textbook '9 + 0' arrangement of microtubule doublets is only present at the primary cilium base. A few microns out, the architecture changes into an unstructured bundle of EB1-decorated microtubules and actin filaments, putting an end to a long debate on the presence or absence of actin filaments in primary cilia. Our work provides a plethora of insights into the molecular structure of primary cilia and offers a methodological framework to study these important organelles.

Details

Original languageEnglish
Pages (from-to)1115-1124
Number of pages10
JournalNature structural & molecular biology
Volume27
Issue number12
Publication statusPublished - Dec 2020
Peer-reviewedYes
Externally publishedYes

External IDs

PubMedCentral PMC7610599
Scopus 85091606266
ORCID /0000-0003-0475-3790/work/155291300

Keywords

Keywords

  • Actin Cytoskeleton/metabolism, Animals, Cell Culture Techniques, Chlamydomonas/metabolism, Cilia/metabolism, Cryoelectron Microscopy, Dogs, Electron Microscope Tomography, Gene Expression, Humans, Madin Darby Canine Kidney Cells, Microtubule-Associated Proteins/genetics, Microtubules/metabolism